Air compressor pump with condensing chamber

ABSTRACT

An air compressor pump is provided, including a crankcase with an opening and a crankshaft extending out of the opening; a cover disposed over the opening in the crankcase; and a condensing chamber formed between the crankcase and the cover.

RELATED APPLICATION

The present application claims priority under 35 US 119 from U.S.Provisional application No. 62/358,973, filed Jul. 6, 2016.

BACKGROUND

This disclosure relates generally to a pump for an air compressor, andmore particularly to a belt driven oil-lubricated pump for an aircompressor.

Air compressors are commonplace in home and commercial workshops. Ingeneral, an air compressor is a machine that decreases the volume andincreases the pressure of a quantity of air by mechanical means. Airthus compressed possesses great potential energy, because when theexternal pressure is removed, the air expands rapidly. The controlledexpansive force of compressed air is used in many ways and provides themotive force for air motors and tools, including pneumatic hammers, airdrills, sandblasting machines, paint sprayers, and others.

A conventional air compressor includes a storage tank for compressedair, and a prime mover mounted on the compressor tank for compressingthe air flowing into the compressor tank. The prime mover may be a gasengine or an electric motor, but many conventional models utilizeelectric power.

The basic components of an electric air compressor are an electricmotor, a pump, a pressure switch, and a tank. The electric motor powersthe pump which compresses the air and discharges it into the tank. Forconventional air compressors, compressed air from the pump is dischargedthrough a tube and a check valve into the tank. The check valve preventsair from flowing out of the tank back through the tube when thecompressor pump is not in operation. Compressed air is stored in thetank.

The pump associated with such air compressors typically includes acrankcase and a crankshaft extending out of the crankcase. Thecrankshaft is driven by the electric motor. To seal the crankcase, acover is mounted on the side of the crankcase through which thecrankshaft extends. The cover typically supports the crankshaft and ismade out of cast iron or other similar material.

Additionally, in pumps that are oil lubricated, the cover functions as aheat exchanger. More specifically, a fly wheel is usually disposed onthe crankshaft and used to blow air onto an outer surface of the cover.Within the crankcase, some oil vapor in the hot pressurized air maycontact with an inner surface of the cover and be condensed back intoliquid oil. In order to allow hot air from within the cover to bevented, the cover typically includes a breather or other ventingstructure.

In use, as hot air leaves the crankcase, through the breather in thecover for example, some oil vapor is often vented to the atmospherealong with the hot air. This loss of oil vapor in the hot air vented tothe atmosphere increases the oil consumption of the compressor pump asthe pump continually loses oil in the vented hot air. Additionally, theoil vapor in the hot air that has been vented has a tendency to condenseon the outside surface of the compressor pump, creating a dirty andundesirable appearance.

Thus, there is a need for developing a compressor pump which effectivelyand efficiently condenses oil vapor within the crankcase, lowering theamount of oil lost via the exiting hot air and, thereby decreasing theoil consumption of the compressor pump.

SUMMARY

The present disclosure is directed to a compressor pump having acondensing chamber which allows oil vapor to be condensed and retainedwithin the crankcase. An important feature of the present condensingchamber is that the condensing chamber is formed by a baffle shaped asan annular ring disposed between a crankcase and a crankcase cover. Thisconfiguration provides a seal between the crankcase and the crankcasecover. Additionally, the baffle provides improved alignment between thefront and rear crankshaft bearings. Furthermore, this configurationallows for oil vapor to enter the condensing chamber and controls theflow of same. The baffle also facilitates the return of liquid oil tothe crankcase after the oil has been condensed in the condensingchamber. In the preferred embodiment, the baffle is made of elastomericmaterial, but is also contemplated as being made of plastic or metal.Finally, it is thought that the baffle additionally functions as athermal barrier between the hot crankcase interior and the cooler innercavity of the condensing chamber. In other words, the presentelastomeric baffle is constructed and arranged so that it insulates andforms a barrier between the condensing chamber which has cool aircirculating across it, and the internal sump of the crankcase which hasa mixture of hot oil, oil vapor and air.

Another important feature of the present compressor pump is that thecover for the crankcase includes ribs that protrude into the condensingchamber. It is believed to be particular advantageous if the ribs alsoextend outward from the outer surface of the cover. As described ingreater detail below, such a configuration is believed to maximizecooling efficiency and condensation of the oil vapor back to a liquid.

Additional aspects, embodiments, and details of the present disclosure,all of which may be combinable in any manner, are set forth in thefollowing detailed description of the disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

One or more exemplary embodiments of the present disclosure will bedescribed below in conjunction with the following drawing figures, inwhich:

FIG. 1A shows a front and side perspective view of the present aircompressor pump;

FIG. 1B shows a rear and side perspective view of the present aircompressor pump;

FIG. 2 shows a side and front partially-exploded, perspective view ofthe present air compressor pump;

FIG. 3 shows a side cutaway view of the present air compressor pump;

FIG. 4 shows a rear and side perspective view of the internal crankcasefor the present air compressor pump; and,

FIG. 5 shows a rear and side partially-exploded, perspective view of theinternal crankcase for the present air compressor pump.

DETAILED DESCRIPTION

With these general principles in mind, one or more embodiments of thepresent disclosure will be described with the understanding that thefollowing detailed description is not intended to be limiting.

As shown in FIGS. 1A and 1B, an air compressor pump generally designated10 includes a crankcase 12, a cylinder 14, disposed on top of thecrankcase 12, and a head 16, disposed on top of the cylinder 14. A valveplate 15 is optionally disposed between the cylinder 14 and the head 16.A crankshaft 18 extends out an aperture 20 (see FIG. 2) in the crankcase12.

The air compressor pump 10 is typically part of an air compressor thatincludes a tank (not shown), for example a 20-gallon cylindrical tank.Additionally, the air compressor includes a motor (not shown), typicallyan electric motor that can be powered via a typical AC wall outlet.However, other motors or power sources such as gasoline engines arecontemplated. The particular sizes, shape, or configuration of the tankor motor is not believed to be important for the understanding of thepresent disclosure. Exemplary air compressors are described in, forexample, U.S. Pat. No. 7,789,102 the entirety of which is incorporatedherein by reference.

Returning to FIGS. 1A and 1B, a cover 22 is disposed over the aperture20 (FIG. 2) and is preferably secured with fasteners 24 or the like. Ascan be seen, the crankshaft 18 passes through the center of the cover22. As will be discussed in more detail below, an outer surface 26 ofthe cover 22 includes a plurality of ribs 28, or projections, extendingaway from the outer surface 26 of the cover 22. In a preferredembodiment, while other materials known in the art are contemplated, thecover 22 is made of aluminum to increase the heat transfer or heatexchange proprieties of the cover 22. A vent aperture 30 is disposed in,and passes through the cover 22.

Turning to FIG. 2, disposed between the cover 22 and the crankcase 12 isa baffle 32, preferably configured as an annular ring. Additionally, afront crankshaft bearing 34 and crankshaft seal 35 are preferablydisposed in a cylindrical housing 36 formed in the center of the cover22. In the preferred embodiment, the baffle 32 is made of anelastomeric, rubber-like material. A variety of conventional durable,flexible, oil-resistant materials are considered suitable for the baffle32. In addition, it is contemplated that the baffle 32 is made ofsuitable plastics or metals.

The baffle 32 includes a center opening 38 that is preferably sized toallow the front crankshaft bearing 34 and crankshaft seal 35 to passtherethrough. In the preferred embodiment, the diameter of the centeropening 38 is dimensioned to maintain a sealing contact with a generallycylindrical, inwardly projecting formation 22 a on the cover 22 (FIG.5). The baffle 32 includes a planar portion 33 having an outer perimeterand a wall 37 extending away and generally normally from the planarportion 33 along the outer perimeter. An inner surface of the wall 37 isoptionally notched or grooved. The baffle 32 also includes a positioningaperture 40 and a condensing chamber aperture 42 both disposed in theplanar portion 33.

With reference to FIGS. 3 to 5, the positioning aperture 40 of thebaffle 32 receives a post 44 in an inner surface 46 of the cover 22.This facilitates the positioning and orientating of the baffle 32 inrelation to the cover 22 to create a condensing chamber 48. Thecondensing chamber aperture 42 allows for fluid communication betweenthe crankcase 12 and the condensing chamber 48.

Preferably, the positioning aperture 40 and the condensing chamberaperture 42 are disposed on opposite sides along the circumference(i.e., 180 degrees apart along the circumference) of the baffle 32. Forexample, the positioning aperture 40 is preferably disposed proximatethe top (relative to orientation in FIGS. 3 to 5) of the baffle 32 andthe condensing chamber aperture 42 is disposed proximate the bottom(relative to orientation in FIGS. 3 to 5) of the baffle 32. It iscontemplated in such a configuration that the vent aperture 30 in thecover 22 is disposed proximate the top (relative to orientation in FIGS.3 to 5) of the cover 22 (similar in position to the positioning aperture40). This will create a long path for the hot air from the condensingchamber aperture 42 to the vent aperture 30 in the cover 22 to allow formore oil vapor in the hot air to be condensed.

The diameter of the positioning aperture 40 and the condensing chamberaperture 42 is contemplated as varying to suit the application. Incertain exemplary embodiments, the positioning aperture 40 and thecondensing chamber aperture 42 each have a diameter of 6.0 mmPreferably, the condensing chamber aperture 42 is sized to allow liquidto flow out of the condensing chamber 48 and into the crankcase 12 atthe same time that hot air is flowing out of the crankcase 12 and intothe condensing chamber 48.

Turning to FIG. 5, the cover 22 preferably also includes ribs 50 orprojections extending into the condensing chamber 48. The ribs 50increase the heat exchange between the hot vapors inside of thecondensing chamber 48 and the cooler air outside of the cover 22.Preferably, the ribs 50 inside of the condensing chamber are eachaligned with one of the ribs 28 on the outer surface 26 of the cover 22to increase the heat transfer.

In operation, as the crankshaft 18 is rotated by a motor (not shown),pistons 52 a, 52 b will move in and out of the cylinder 14 compressingair, as is known, which can be discharged to and stored in the tank (notshown). The movement of the pistons 52 a, 52 b and/or the rotation ofthe crankshaft 18 will also generate heat within the crankcase 12. Asoperation continues, the heat will vaporize oil 54, creating oil vaporin the hot air within the crankcase 12. The hot air, with the oil vapor,passes through the condensing chamber aperture 42 and into thecondensing chamber 48.

A fly wheel (not shown) is typically disposed on the crankshaft 18proximate the cover 22 and will force relatively cool air towards theouter surface 26 of the cover 22. Within the condensing chamber 48, thehot air with the oil vapor contacts the inner surface 46 of the cover 22and/or the ribs 50 (if present), causing heat to be absorb therefrom.The heat will be transferred to the ribs 28 on the outer surface 26 ofthe cover 22 and may be absorbed by cool air from the flywheel,discussed above. Inside of the condensing chamber 48, after heat isremoved from the oil vapor, the oil vapor condenses into liquid oil. Theliquid oil in the condensing chamber 48 passes through the condensingchamber aperture 42 and into the crankcase 12. Hot air in the condensingchamber 48, which is lean in oil vapor, is preferably vented to theatmosphere from the condensing chamber 48 through the vent aperture 30.

In the preferred embodiment, the baffle 32 additionally functions as athermal barrier between the hot crankcase interior and the cooler innercavity of the condensing chamber 48. In other words, the present baffleis constructed and arranged so that it insulates and forms a barrierbetween the condensing chamber 48, which has cool air circulating acrossit, and the internal sump of the crankcase 12 which has a mixture of hotoil, oil vapor and air.

Compared to existing air compressors pumps, the hot air exiting an aircompressor pump according to the embodiments of the present disclosurewill have less oil vapor in the vented hot air. This will decrease theloss of oil for the air compressor and accordingly decrease theconsumption of same. Also, the exterior surface of the air compressorpump will not accumulate oil as quickly. Furthermore, the use of thepresent condensing chamber allows for a simpler venting structure, i.e.,an aperture or the like, as opposed to breather or other such devicetypically used in conventional devices. The aperture also allows for thecrankcase to vent even if the air compressor pump is not in operation,for example while the air compressor pump is being filled with oil.Additionally, the air compressor pump with the cover allows for easierconstruction and assembly of the air compressor pump.

While at least one exemplary embodiment has been presented in theforegoing detailed description, it should be appreciated that a vastnumber of variations exist. It should also be appreciated that theexemplary embodiment or exemplary embodiments are only examples, and arenot intended to limit the scope, applicability, or configuration of thedisclosure in any way. Rather, the foregoing detailed description willprovide those skilled in the art with a convenient road map forimplementing an exemplary embodiment of the disclosure, it beingunderstood that various changes may be made in the function andarrangement of elements described in an exemplary embodiment withoutdeparting from the scope of the disclosure.

What is claimed is:
 1. An air compressor pump comprising: a crankcasewith an opening and a crankshaft extending out of the opening; a coverdisposed over the opening in the crankcase; and a condensing chamberformed between the crankcase and the cover.
 2. The air compressor pumpof claim 1 further comprising: one or more ribs disposed on an outersurface of the cover, or an inner surface of the cover, or both.
 3. Theair compressor pump of claim 1 further comprising: a baffle disposedbetween the crankcase and the cover, disposed for defining thecondensing chamber.
 4. The air compressor pump of claim 3 furthercomprising: a positioning aperture and a condensing chamber apertureboth being disposed in the baffle.
 5. The air compressor pump of claim 3further comprising: a vent aperture disposed in the cover.
 6. The aircompressor pump of claim 3, wherein said baffle is constructed andarranged to form a thermal barrier between the condensing chamber, whichhas relatively cool air circulating across it, and the internal sump ofthe crankcase, which has a mixture of hot oil, oil vapor and air.
 7. Theair compressor pump of claim 3, wherein said baffle is made ofelastomeric material.